Social, economic and health inequalities are experienced worldwide. Although around 21% of the developing world lives on less than US$ 1 per day, this statistic masks the unfathomable distress in sub-Saharan Africa, where almost half of the population lives in abject poverty. It is hard to appreciate fully the reality of this; that in addition to the daily material hardship and poor physical health, there is the accompanying social exclusion, inherent poverty of choice and connection, and likely impact on mental well-being. This is exemplified by food, a topic covered in this book. Poverty is synonymous with hunger, but food is much more than nutrition for health. It is an expression of who a person is and what they are worth. It acts as "social glue"; the environment in which food is prepared, distributed and consumed serves to reinforce social relations and cultural norms. Living in poverty provides little opportunity to achieve good health and nutritional status, or to feel part of daily social life and networks. In today's world of extraordinary economic growth, excesses in global food supply, availability of health technology on a scale never before imagined, and where US$ 380 billion is spent annually on health services in low- and middle-income countries, it is unfair and unjust that anyone should lack the opportunity to pursue health and avoid hunger.

Responding to the health and social needs of the most underprivileged populations is a major public health challenge. In their book, Gwatkin et al. draw attention to the need for information which tells policy-makers both the extent of the health problem and, more importantly, what to do about it. Refining the quality and sensitivity of empirical data, and showing the urgency of the problem among the most disadvantaged groups in society, has undoubtedly helped inform policy and action, and indeed, many pro-poor health-related interventions exist worldwide. However, many interventions do not reach those most in need, and many perpetuate and exacerbate the health gap between rich and poor; in the 21 countries studied in the World development report 2004, the highest income quintile received, on average, 25% of government health service expenditure compared with only 15% among the lowest quintile.

Investigating the question of what health service interventions exist, do they work and for whom, Gwatkin et al. draw together work from the Reaching the Poor Program (RPR). Instigated by the World Bank, RPP aims to identify the extent of inequality in coverage of health service interventions, with the main objective being to ascertain interventions which do successfully serve the poor. Using 11 case studies of health service programmes aimed at the poorest in Africa, Asia and Latin America, the book highlights the complexity of key technical matters, such as data availability, quality, and measurement issues of inequality, access and use of health services. The authors, however, are not constrained by technical matters, and present several encouraging success stories. For example, in Argentina, over half of whose population was living in poverty in 2002, three child-feeding programmes covering milk for babies in hospital, food in public kindergartens and meals in local feeding centres delivered 40-75% of their benefits to the poorest 20%. Not only did these programmes address the nutritional needs of a substantial proportion of the poorest groups; also they went some way to redress the poverty of choice and connection experienced by socially excluded groups.

This book will be of immense interest and benefit to readers who care about the health of individuals and societies, and who want to broaden their understanding of these issues in a range of health service settings in low- and middle-income economies. Recent reports of widening gaps and improvements among the richer groups in society highlight that what is currently in place, in terms of policy and practice, is not adequate. This book, however, provides an evidence base for optimism through its demonstration of which interventions work to provide several health, nutrition and population services to many populations most in need. Nevertheless, a policy-maker or practitioner hoping to pick from this portfolio of success should be cautious. As the book recommends, more work is now needed to explain why and how certain interventions do or do not reach the poor. Several of the individual chapters refer to issues of transferability, and the text deals implicitly with aspects of organizational complexity and scale. Unless it can be demonstrated explicitly how these matters impact on the success of an intervention, the knowledge necessary for successful utilization at the local level remain elusive.

As Gwatkin et al. highlight, a crucial component of a concerted approach to redressing inequalities in population health is support of the health of the poorest in society through targeted health service interventions. This must be part of a wider global movement to address the gap between rich and poor and the gradients in health across all groups within and between societies. Pursuit of such health equity recognizes implicitly the need to redress the unequal distribution of opportunity to be healthy, the responsibility and capacity for which often lies outside the health care system. This focuses attention not only on the relief of poverty but also on the wider social determinants of health, including upstream global and national level social, environmental and economic conditions within which people live, and more immediate factors such as employment, education, housing, quality of living environments and social relationships.